#myBtn
{
  display: none;
  position: fixed;
  bottom: 10px;
  right: 15px;
  z-index: 99;
  font-size: 10px;
  font-family: Arial, Helvetica, sans-serif;
  font-size: 12px;
  border: none;
  outline: none;
  background-color: black;
  color: white;
  cursor: pointer;
  padding: 10px;
  border-radius: 4px;
}

#myBtn:hover {
  background-color: #555;
}